Sound system



June 2, 1936. J. H. HAMMOND, JR 2,042,999

SOUND SYSTEM I Filed Dec. 23, 1933 5 Sheets-Sheet 1 Tympani awvemtoz 8% a, @awli June 2, 1936. J. H. HAMMOND, JR

SOUND SYSTEM Filed. Dec. 25, 1953 5 Sheets-Sheet 3 ae wwtoz 4 /7% m 4 June 2, 1936.

.1. H. HAMMOND, JR

SOUND SYSTEM 5 Sheets-Sheet 4 Filed Dec. 23, 1933 June 2, 1936- J. H. HAMMOND, JR

SOUND SYSTEM Filed Dec. 23, 1933 5 Sheets-Shegt 5 To Other Posifions avwemboz ado (MW V4 Patented June 2, 1936 UNITED STATES PATENT OFFICE 16 Claims.

The invention relates toacoustics, and more particularly to systems for rendering sound prorams from a number of different sound sources simultaneously.

The invention relates to systems for improving the eflects of orchestras by modifying the amounts of sound emanating from the various instrument groups. The invention is also applicable to other sound originating systems, such as those used for making talking moving pictures.-

According to a preferred form of the invention, a single primary or main pick-up is located centrally of the orchestra to pick-up the entire orchestra in the usual manner. In addition, a plurality of secondary or -auxi'liary pick-ups are provided, one pick-up for each musical instrument or group of musical instruments. Suitable devices are provided for proportioning the relative intensities from the several secondary or auxiliary pick-ups. Further arrangements are provided for proportioning the amount of sound from the main or primary pick-up with-respect to the secondary or auxiliary pick-ups taken as a whole.

The invention further contemplates a mechanical, multiple potentiometer arrangement under the control of the orchestra leader for proportioning the sounds picked up from the several sec-: ondary pick-ups. This control may be accomplished by a single knob or handle cooperating with a diagram indicating the layout of the orchestra. By moving the handle in position corresponding to the instrument groups in the diagram, the desired instruments may be emphasized correspondingly. The potentiometer arrangement may be such as to maintain the total amount of sound picked up from the secondary pick-ups substantially constant. A further mechanical device may be provided for proportion- Fig. 2 is aesectional plan view taken 'on line' 2-4 of Fla. 3:

' Fig. 3 is a. sectional elevationtaken on line 3-3 of Fig. 2.

Fig. 4 illustrated diagrammatically the pick-up 5 devices with their associated circuits.

Fig. 5 illustrated diagrammatically a transmitter and a recording system used in connection with the circuits shown in Fig. 4.

Fig. 6 shows a modifiedform of control handle. 10

Like reference characters denote like parts in the several figures 'of the drawings.

In the following description and in the claims, parts will be identifiedby specific names for convenience, but they are intended to be as generic 15 in their application to similar parts as the art will permit.

Referring more particularly to the form of the invention shown in Figs. 1 to 3 a framework I0 is mounted in a casing I I which is provided with 20 a top l2 of translucent material such as ground glass. This top is provided with an opening. l3. Etched, or otherwise marked "on this plate, are the locations of the various groups of instruments of the orchestra such for example as the 2 violins, cellos, etc. Also, a square ll denoting the location of the orchestra leader.-

Pivoted to the frame It are two links I! and I. the ends of which are connected together by a link II, to the' ends of which are pivoted links I8 and I9. Pinned to the end of the link I8 is a shaft it upon which is rotatably mounted one end of a link 22 in theother end of which is rotatably mounted a shaft 2!, the rounded lower end of which rests on the casing II. This shaft is also rotatably mounted in the end of the link ll. Twocollars 24 are pinned to the shaft 23 for holding the links is and 22 in their proper positions. Pinned to the upper end of the shaft 23 ing the relative sound between the primary and 1 a knob 25 made of insulating material. Below secondary pick-ups, operable preferably after the setting of the multiple potentiometer arrangement. Althoughthe novel features which are believed to be characteristic of this invention will be particularly pointed out in the claims appended hereto, the invention itself, as to its objects and ad-' vantages, the mode of its operation and the man ner of its organization may be better understood by referring to the following description taken in connection with the accompanying drawings forming a part thereof, in which Fig. l is a top plan view of a mechanism constructed in accordance with this invention.

this is slidably mounted a second knob 2,,also made of insulating material which no rests against a collar 27. Between these Obs is a spiral spring 28 which-normailyiholds them apart. Located in each knob isa contact 3| and 32 r espectively.

Rotatably mounted on the shaft 2| are seven square rods 33 to 39. These rods slide in sleeves ll to 41 which are mounted on shafts 43. These shafts are rotatably mounted in the frame II and have collars l9 secured to their lower ends. Secured to the sleeves to 11 are seven strips of insulating material It to IT, on which are mounted seven resistances I to |I. Attached 6 Q 45 Dlifier I22, and an oscillator I23.

to but insulated from the rods 33 to 30 are seven contacts II to II. Attached to the upper end of the shaft 2I is a cylindrical casing I3 in which is mounted a lamp I which is supplied with current from any suitable source, not shown.

Referring'more particularly to the wiring diagram shown in Figs. 4 and 5 a primary microphone II is located in a suitable position with respect to the entire orchestra so that it will pick up the sounds from all the instruments. This microphone is connected through a transformer 32 to a potentiometer 83 the other side of which is connected to the input circuit of a group of amplifiers 34, 35, and 06, the output circuit of which is connected to the primary of 'a transformer 01. A plurality of microphones some of which-are indicated at SI, 32, and 93 are located with one microphone over each group of instruments of the orchestra, such -for example, as the first violins, cellos, etc. The microphones SI, 9:, and 93 etc. are connected through transformers 94, 85, 95, etc. to the resistances SI, 62, 63, etc., engaging these resistances are the slidable contacts II, I2, I3, etc. which are connected to themput circuit of groups of amplifiers, S'I and st, the output circuits of which are connected in parallel to the primary of 'a transformer 30. The secondaries of the transformers 31 and 99 are connected to resistances ,III and I02. Cooperating with these resistances are slidable contacts I03 and I04 which are connected to the input circuit of a space discharge amplifier I05, the output circuit of which is connected through a transformer I" to the input circuit of a pushpull amplifier III the output circuit of which is connected to the primary of a transformer I08. This transformer is provided with two secondaries I05 and III. The secondary I03 is connected by two conductors II2I I3 to one side of a doublepole single-throw switch IIO, the other side of which is connected to aradio broadcast trans 'm'itter I I I which is of standard and well known construction and which includes two modulator tubes III and II, afilter circuit I2I, apower am- The output circult of the power amplifier I22 is connected to an antenna I24. a

The secondary I I I is connected by two conductors II4 and,I II to one side of a double-pole singi ihmw switch as, the other side of which is connected to the engraving mechanism I25 of a phonograph recorder I 2]. The engraving mech- V anism I24 is mounted on an arm I23 which is pivotally connected to a shaft I20. The engraving mechanism I24 is provided with an engraving tool |3I which engraves the upper surface of a record tablet I32. This tablet rests upon a disk I33 which is secured to afshaft I3 4 which is drivenby the phonograph mechanism. This mechanism also drives the shaft I20 at 'a very slow rat'e'so,

that the engraving tool I 3| cuts a spiral track on the upper surface of the record tablet I32.

The slidable contacts I03 and I04 are mounted upon a rod of insulating material III to the upper end of which is secured a piston I42 ,slidably mounted in a cylinder I43. .This cylinder is pro-- vided with a vent m, the size of which is adjusted by means of a knurled knob I45. The other In theoperation oi the form of the invention from the orchestra is picked up by the primary or main microphone 8| and amplifledby the amplifiers 04 and 35 and 05. This amplified current then passes through the transformer 01 to the resistance I III where normally all of this energy 5 is picked up by the contacts I03 and I04 and fed to the amplifier I05 and push-pull amplifier Ill. The energy then passes either to the broadcast transmitter III or to the phonograph recording a mechanism I2'I depending upon whether the 10 switch IIO'or I25 is closed. If the switch H6 is closed, the music is transmitted from the antenna I24 by the broadcast transmitter H1 in a well-known and standard manner which need not be more fully described herein. If the switch I25 15 is closed, the engraving tool I3I will cause a sound record to be made on the tablet I32 as it is rotatedunder this tool.

The sound picked up by the microphones 9 I, :2, 83, etc. will be amplified by the groups of ampli- 20 fiers 01 and 83, but will not be fed to the amplifier I05 as the contact I04 is normally so set that no energy will be picked up from'the resistance I02. If the orchestra leader desires to accentuate a certain group of instruments in 25 the orchestra, such as the cellos for example, he first moves the knob 25 upward and to the left until the light I! is moved toward the position marked cellos on the cover I2. In doing this the rod 34 will be moved to the left thus causing the. 30 contact I2 to slide over the resistance 52 in a direction to cause an increased pick-up from this resistance. Thereby the amount of resistance 52 in the input circuit of tube 91 will be increased. At the same time the contacts II and I3 will be moved a smaller amount over their resistances in the same direction and the contacts I5, I6, and I1 wili be moved various amounts over their resistances in the opposite direction. The ad justment of knob 25, as above described, of itself 40 causes no eifect on the music.

To put the accentuation of the cellos into effeet the orchestra leader squeezes the knobs 25 and 25 together, thus closing the circuit through the solenoid 1-. This causes the core I46 together with the rod I ll tolbe moved downward,

the, speed of this motion being determined by the dash pot action of the piston I42 and the cylin-' der I43, the speed of thisbeing controlled by the size.of the opening of the vent I44.

This causes the contacts I03 and I04 to move downward over the resistances "I and I02 at a predetermined rate of speed. As they do so, the amount of energypicked up from resistance IOI decreases and that picked up from resistance I02 increases. In this way the amplified energy from the primary microphone 3|, which is fed to the amplifier I05, is. gradually decreased and the amplified energy from the microphones SI, 02, and 93, etc., which is also fed to the amplifier III, is increased. It is .thus seen that by this mixing device' it is possible to combine the amplified energy of the two systems of pick-up so that the recording mechanism I2I, as desired.

If the orchestra leader desiresito accentuate the brasses, he moves the knob 25 to the right and upward so that the light 10 is moved in this direction, this motion being apparent to the orchestra leader by the bright spot of light travelling over the ground glass I2 toward the position marked Brasses on the glass... --This will'cause the contact I! to move over the resistance so that more energy will be picked up from the microphohe located over the brasses. The orchestra leader then squeezes the knobs: and 20 together thus reproducing the operation already described.

It is thus seen that by moving the knob 25 in various directions it is possible to adjust thepick-up systems togive the same eil'ect as if the main pick-up device were moved toward whichever group of instruments it is desired to accentuhaps barely perceptible while. others are-overemphasized. With the present invention it is possible for the director, by adjusting the setting of the potentiometers before recording starts and leaving the adjustment constant during the recording of aselection, to compensate for these faults in the recording system and to bring the weakly recorded instruments up to their normal volume.

Although in the-form of the invention shown, the system for recording isshown in connection with the recording of ordinary phonograph records it is to be understood that it is not hunted to this method, but may be used with other forms of recording, such as for making a sound record 'on a moving picture film in any well-known manner. i a

In the modified form of the invention shown in Fig. 6 the mechanism is similar to that described in connection with the previous figures, with the exception of that associated with the knobs 25 and 26. In this form the contacts 3| and 32 are eliminated and a rod Iii is attached to the lower knob 2'. This rod is pivoted to an arm III-which is .rotatably mounted upon a collar I53 which is pinned to the shaft 23. The other end of this arm'is pivoted to a. rod of insulating material I 54 which slides in a member IE5 also made ofinsulatin'gmaterial which is pinned to the shaft 23. Secured to'therod I is a-contact I58 which is connected to one side of the winding of the solenoid I ll. Mounted on the member I55 .is a resistance I", one end of which is connected to one side of the battery I 49.

The operation of the modified form of the inthe two knobs 25 and 2! are in contact. In this way it is possible for the orchestra leader to adjust the current passing through this solenoid to any desired value by suitably manipulating the knobs II and 2. He can thus determine the ilnal positions ofthe contacts I and I which in turn .will determine the amount of energy picked up from the resistances III and m. The orchestra leader can, therefore, determine the relative amount of energy which is picked up from the two systems. 7 He thus not only has the means to accentuate any desiredsection of the orchestra,

but also a means for grading this accentuation as desired. 4

Although only a few of the various forms in which this invention may be embodied have been .shown herein, it is to be understood that the invention is not limited to any specific construction, but might be embodied in various forms without departing from the spirit of the invention or the scope of the appended claims;

What is claimed is: .l In an orchestral pick-up system, means for 15 picking up sound from diflerent parts of an'orchestra-in variable proportions, control means for varying said proportions, aZ-surface marked out to simulate the space relationshipof the. parts ,.of said orchestra and an indicator moved by said 20 control means over said surface to give by its position a visual indication'of the relative proportions for which said control means isset.

2. An orchestral pick-up system. comprising a plurality of microphones located respectively over 25 'the various groups of instruments, a plurality of channels including variable transmission devices connected respectively to said microphones, said transmission devices being located in the same spaced relationship as said microphones 30 and manual means for adjusting all of said variable transmission devices' simultaneously and diflerently.

3. In a system-tor translatingsounds emanating from a plurality of sources into electrical as energy, a means for simulatingthe outputof-a single sound pick-up'device movable among said sound sources comprising a plurality of sound pick-up devices distributed among said sound sources, means for combining the energy outputs 40 of said pick-up devices, and a proportioning device for'vario'usly proportioning said outputs, 'said proportioning device including meansfor; maintaining the relative proportions of said outputs the same as that of the energy which would be received from said sources by said single sound pick-up device as it is moved with respect to said sources.

' 4. In a system for translating sounds from a plurality of sources into electrical-energy, a pickup device located near each said source of sound, means for combining the energy outputs of said pick-up devices, and means for variously proportioning said energy outputs, said last means being adapted to automatically maintain predetermined relative proportions between said outputs.

5. A potentiometer control mechanism comprising a plurality of sliding contact potentiometers, a control rod'associated with each of said potentiometers, longitudinal motion of each said rods being adapted to vary the settinglo'f its associated potentiometer, a pivot member, all said rods beingpivoted thereon, and a control member for moving said pivot member about over a predetermined area.

6. In a sound pick -up system, a plurality of pick-up devices distributed in space, a circuit for combining the outputs of said devices in various proportions, a proportioning device for varying said prop rtions, a translucent screen marked to simulate the space relationship of said pick-up devices. a light source behind said screen, and means for controlling'the position or said light source responsive to the setting of said propor- 15 various proportions, a proportioning device for v tioning device whereby the prop r ons oi said outputs are visually indicated on said screen.

7. In a sound pick-up system, a plurality'oi pick-up devices distributed in space, a circuit for combining the outputs of said devices in various proportions, a proportioning device .ior varying said proportions, an indicator adapted to be moved in various directions to simulate the space relationship of said pick-up devices, and means for controlling the position oi said indicator responsive to the setting or said proportioning device vvhereby a visual indication oi. the proportions of said outputs is obtained.

8. In a sound pick-up system, a plurality of pick-up devices distributed in space to separately varying said proportions, an index arranged to simulate the space relationship oi! said pick-up devices, an indicator cooperating with said index, and means for controlling the position of said indicator responsive to the setting of said proportioning device whereby the proportions of said outputs are visually indicated on said index.

9. An orchestral pick-up system comprising a plurality of microphones located respectively over the various groups instruments, a plurality of channels including variable transmission devices connected respectively to said microphones and a single control means adapted to simultaneously and difieren a y adjust all of said devices so as to obtain any desired prop rtion oi the energy from each individual microphone.

-, 10. An orchestral pick-up system comprising a plurality of microphones located respectively over the various groups of instruments, a plurality of channels including variable transmission. devices connected respectively to said microphones and variously disposed about-a center anda central. control means pivotally'connected to-each of saiddevices and adapted to simultaneously and diiierentially adiustsaid devices according to the direction ofmovement thereof.

11. An orchestral pick-up system comprising a plurality of microphones located respectively over the various groups of instruments, a plurality of channels includingvariable transmission devices omnected respectively to said microphones and disposedaboutacenterandacentral' pick-updeviceadistributedinspacetoseparately' pickup energy from apiuralityotiscurces, a circuit torcombiningthe outputsotsaiddevicea in various proportions, a proportioning device for varying said proportions, a pick-up device adapted to pick up energy from all of said sources, a

utili'mtion channel actuated by the combined outpick-up devices distributedin space to separately pick up energyfrom a' plurality 0! sources, a circuit for combining the outputs 01' said devices in various proportions, a proportioning device for varying said proportions, a pick-up device adapted to pick up energy from all of said sources, a utilisation channel actuated by the combined outputs of said first pick-ups and by the output from said last pick-up, means to preset said proportioning device and means to gradually reduce the influence c! said last pick-up and to increase the go influence oi! said first pick-ups on said utilization circuit.

14. In a sound pick-up system, a plurality of pick-up devices distributed in space to separately pick up energy from a plurality of sources, a circuit for combining the outputs of said devices in various proportions, a proportioning device for varying said proportions, a pick-up device adapt-, ed to pick up energy from all oi said sources, a utilisation channel actuated by the combined outputs of said first pick-ups and by the output from said last pick-up, a control handle to preset said proportioning device and means actuated. by said control handle for progressively reducing the infiuence of said last pick-up and progressively increasing the influence oi said first pick-ups on said utilization circuit.

15; In .a sound pick-11D ystem. a plurality 0t pick-up devices distributed in space to separately pick up energy from a plurality oi. sources, a circuit for combining the outputs of said devices in various proportions, a proportioning device for varying said proportions, a pick-up device adapted topick up energy from all-of said sources, a utilisation channel actuated by the combined outputs of said first pick-ups and by the output from said last pick-up !and change-over means to change the utilisation circuit from said last pickup tosaid first pick-up. 18. A control mechanism comprising a plum rality ct sliding'contact devices, a control rod associated with each of said devicu, longitudinalmotionoieachsaidrodsbeing adapted tovary the setting of its associated device, a pivot member,allsaidrodsbeingpivotedthereon,anda control member for moving said pivot member aboutover apredetermined area.

' JOHN HAYS HAlfllOllD, Jr. 4 

